And charles



2 Sheets-Sheet 1.

F. H. 86 0-. H. FIELD. PORTABLE DENTAL CHAIR.

(No Model.)

Patented Sept. '13, .1892;

ca. PNO'IO-LITHQ, WASHINGTON a c 2 +0 6 e h S P t e e h S 2 D L E I P HG & H P d 0 M o PORTABLE DENTAL CHAIR.

No. 482,520. Patented Sept. 13, 1892.

amvamtow':

UNITED STATES PATENT OFFICE.

FRANK HENRY FIELD, OF NElV ORLEANS, LOUISIANA, AND CHARLES IIARMANFIELD, OF DALTON, GEORGIA.

PORTABLE D ENTAL CHAIR.

SPECIFICATION forming part of Letters Patent No. 482,520, datedSeptember 13, 1892.

Application filed June 20, 1891. Serial No. 396,929. (No model.)

To aZZ whom, it may concern.-

Be it known that we, FRANK HENRY FIELD, residing at New Orleans, parishof Orleans, and State of Louisiana, and CHARLES HARMAN FIELD, residingat Dalton, in the county of Vhitfield and State of Georgia, citizens ofthe United States, have invented certain new and useful Improvements inPortable Dental Chairs; and we do declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame, reference being had to the accompanying drawings, and to theletters of reference marked thereon, which form a part of thisspecification.

Our invention relates to dental chairs, and has for its object aconstruction that will allow of the use of an ordinary house-chair bysecuring it to the supporting-frame of the chair so that the supportingmechanism can be easily and readily transported, thus adapting it forthe use of itinerant dentists.

It has, further, for its object to render the parts simple, strong, andinexpensive in construction, and so that they will allow of readyadjustment to suit varying conditions, and may be folded and packed intocompact form in a small space.

It has, further, for its object to provide for lifting the chair by themanipulation of a lever, so that the whole chair can be readily andeasily turned around, as upon a pivot.

To the accomplishment of the above and such other objects as may appearthe invention will be hereinafter more particularly described andclaimed, reference being had to the accompanying drawings, forming apart hereof, and in which Figurel is a perspective of the chair set upin position for use. Fig. 2is a side elevation of the invention, showingthe chair in dotted lines with the arms omitted. Fig. 3 is aperspective, on an enlarged scale, of the footrest. Fig. 4. is a detailviewon same scale as Fig. 3 of the ratchet movement for raising andlowering the chair. Figisadetail perspective, on an enlarged scale, ofthe cups in which the chair-legs rest, one-half in full lines andone-half in dotted lines. Fig. 6 is a rear perspective in detail of thelowerlateral arms and their connection to the brace-bar. Fig. 7 is adetail perspective, same scale as Fig. 6, of the connection of the lowerend of the brace-bar to the base. Fig.8 is a side elevation in detail,same scale as Figs. 6 and 7, ofv

a portion of the head-rest mechanism which engages the chainframe. Fig.9 is an enlarged side view, parts broken away and in section, showingthe means employed to raise the structure when it is desired to turn thesame. Fig. 10 is an enlarged side view, parts being in section, showingthe means of attachment of the handles to the screw-bolts. Fig. 11 is aperspective,on an enlarged scale, of a modified form of the lowerlateral arms. Fig. 12 is a detail plan view, on an enlarged scale, ofthe head-resbadjnsting mechanism, a part being broken away. Fig. 13 isan enlarged side view, parts being in section, of the means forattaching the standard to the base.

In the drawings the letterA designates the base of the supporting-frame,which has four hollow arms B extending horizontally therefrom and twohollow arms B and B one ex tending upward and the other downward, thewhole forming a six-way T or coupling. This coupling receives in itshorizontally-extending portions the fourarms O, which may screw into thecoupling so as to be readily separated for transportation. These arms 0are preferably made of metal tubing, and the end of each arm may have aknob or elbow D screwed onto the same, which knobs are represented asprovided with rollers E, so that the chair may be easily moved from oneposition to another.

The upright portion B will have a standard F suitably secured to it,preferably by screwing into it, and further braced thereto by a clamp G,whichcan be tightened or loosened by turning the bolt on by the handleI),

which is pivoted to the head of the .bolt..

This standard is formed with gear-teeth or rack-bar H on one faceextending lengthwise thereof, which face is preferably flat or formedwith flat sides, as shown, for the purpose of guiding and preventingfrom turning a sleeve The teeth of this bar fitted to the standard.

are set so that a worm-pinion may gear with them. This sleeve justreferred to is desigcarried by the sleeve I.

ered to' adjust the chair to the desired height.

This worm also serves to lock the sleeve to its adjustment so that itcannot slip. The sleeve I is also formed with laterally-extending arms0, which are preferably tubular and fitted into sockets P, formed in thesleeve, and which arms carry at or near their ends cups or sockets Q,set in a position to receive the rear legs of a chair B. These cups orsockets are made separate from the arms 0 and cast with collars S,through which the arms will pass and to which they will be secured, soas to be free to turn, as on a hinge, and by thus forming them they maybe adjusted to or from each other to suitthe width apart of thechair-legs, and at the same time turned, as on a hinge, to suit theinclination desired. It is preferred to make these sockets, as well astheir collars, in two parts, the line of division being verticallythrough the sockets and the neck 0, which connects them to theircollars, and transversely through the collars, as indicated in Fig. 5.In such case the two parts will be held together by a bolt d, passedthrough the two parts of the neck 0, as illustrated in the same figure.By constructing the sockets in the manner just described they may beadjusted to fit the foot of the leg of an ordinary chair.

The upper portion of the chair is supported against a bracket T, whichis provided with laterally-extending arms U, formed at their ends withthe upwardly-turned hooks e to fit under a cross-bar of a chair, asillustrated. This bracket T is preferably in the form of a sleeve,through which a bar or rod V may pass, and is slitted vertically andformed with ears f, through which a bolt Q will pass, so thatbytightening up the bolt the sleeve will be clamped around the rod, andthus hold the rod at the adjustment desired. Between the ears f of thesleeve-bracket T there is placed one end of a pin or stem h, formed withan eye at that end, through which the bolt g passes to hold the pin inplace. The connection between the pin and bolt is loose, so that the pinacts as a pivot or hinge for the bracket. The head of the bolt g has ahandle 11, swiveled or pivoted to it, by which to turn the bolt. Thelower end of the pin or stem h fits into asocket formed in the upper endof a two-part braced rod or bar W and is held therein by a set-screw k.The

two parts of the brace-bar W enter a sleeve X, which is secured rigidlyto the lower part of the bar,but in which the upper part of the bar isfree to slide. The upper part or sliding portion of the bar is providedwith teeth Z, with which engage a pinion m, journaled in ears n to thesleeve, said pinion being revolved by a worm o, journaled in anoverhanging arm or bracket 19 of the sleeve and operated by a crank q.By means of the crank q the brace-rod WV is lengthened or shortened asthe inclination of the chair is changed, the inclination of the chairbeing accommodated by the hinging of the bracket T to the bracerod W, ashereinbefore set forth. In the lower part of the bar WV a socket isformed, into which fits a pinj, pivoted between the cars and held in thesocket by a setscrew Z, thus hinging the rod at its lower end.

The upper part of the rod V has secured to it a hook Y, designed to fitover a cross-bar or round to the chair, so as to prevent the chair fromslipping or being accidentally pushed upward out of place, and also toaid in preventing it from accidentally tilting forward.

There extends rearwardly from the rod V a bifurcated arm Z, which at itsinner end is hinged or pivoted to ear r, projecting from a portion ofthe rod. There also projects from the rod V a segment 0, pivoted orhinged at one end to ears 8, projecting from a portion of the rod andpassing through the bifurcation of the arm Z. The purpose of thissegment is to hold the arm Z at the necessary inclination to sustain atthe desired height a headrest hereinafter described, the object beingeffected by clamping the arm to the segment by appropriate means,suitable means therefor to be presently described. The segment 0' mightbe rigid, but it is preferred to pivot it, as it can then be more easilyplaced in position in the bifurcated arm Z. To the end of this arm thereis pivoted or hinged an arm Z, which is provided with a segment 0passing through the bifurcation of the arm Z. The purpose of thissegment 0 is to hold the arm Z to the position to which it may beadjusted to or from the chair, the segment being clamped at the desiredposition by the bifurcated arm Z. By the use of the two armsZ and Z,hinged as described, and the two segments 0 and C the head-rest Dsupported by the arm Z, may be raised orlowered and adjusted to or fromthe chair to the position desired by simply loosening the means whichclamp the two segments and afterward tightening them up to hold thehead-rest to its adjusted position. The preferred means for clamping thesegments to the arms Z consists of a shouldered and threaded bolt 25,passed through the bifurcated arm Z and having a nut 7.6, provided witha handle 1), applied to it, so that by turning said nut the two sides ofthe bifurcated arm will be drawn toward each other and caused tobearagainst and clamp the two segments, thereby holding the arms Z and Z tothe adjustment desired. It is obvious that either arm may be adjustedindependently of It is preferred to place a block w the other.

in the arm Z adjacent to the bolt t, so as to guide the segment C if itbe pivoted.

A detachable foot-rest is provided for the chair and consists of twobars D, whose inner ends converge, as shown at 2, and areconnectedtogether at 3 by a bolt 00, at which point there is alsopreferably placed a spacing-block y, and at or about the point 3 thereis passed through the bars a bolt 5 in such manner as to prevent thebars from spreading apart, but allowing them to be brought together bythe screw G. The bars D have pivoted to them the suspending-arms E,provided at their upper ends with books a, intended to fit over a roundof the chair, so as to suspend the foot-rest from the chair. It ispreferred to bolt together the arms, as at 4. There is connected to thema segment F, which passes between the bars D, as shown at 5, and isclamped and held rigid by drawing the two arms tightly against it bymeans of a threaded bolt or screw G, passed through the two arms andformed with a shoulder b to bear against one arm and with a handle H forconveniencein manipulating it. By loosening the screw or bolt G thefoot-bars D can be adjusted to the angle of inclination desired and heldthere by tightening the bolt.

It is preferred to have the foot-rest bars to diverge somewhat from eachother at their free ends, but so that they may be pressed inwardlytoward each otheigin order that when they are passed through the sleevesI to the foot-rest board J the tendency of the bars to spread outwardlyto resume their normal state will create friction or pressure enoughagainst the sleeves to hold the foot-board in any position to which itmay be adjusted on the bars.

Into the downwardly-projecting portion B of the six-way T there extendsa stem K from the base-iron L, said parts being held against becomingdetached by a pin 0, passing through the part B and fitting in thereduced portion d of the stem K. While the parts are thus held againstdetachment the coupling is permitted to move up and down on the stem Kas well as to turn about the same, so that the rollers E, whichconstitute the feet of the structure, may be lifted wholly from 01f theiioor, and thus permit the Whole structure to be swung or turned aroundto any extent desired. Thelifting of the structure is effected by meansof a wedge M, hearing against the top of the stem K and a portion of theT-ooupling,whioh portion may be a bearing-block f, cast as a part of thecoupling and having a beveled under face, as indicated in Fig. 9.. Thiswedge is attached to a rod N, extending through one of the hollow arms 0and knobs D and formed with a collar 0 at its outer end, which fitsaround an eccentric P, having its bearing on the ears 9 and providedwith a lever Q, adapted to be operated by the foot to turn the eccentricand through it move the rod N in or out, the

lever Q being provided with a pin it, bearing against the periphery ofthe collar 0 and serving to limit the throw of the lever. The normalposition of the foot-lever Q and wedge M is shown in Fig. 9. By pressingthe footlever in the direction of the arrow the wedge M is forcedbetween the stem K and bearingf, and as it is pushed between said partsit forces the whole structure above the baseiron L upward, so as to liftthe feet from 01f the floor and allow the structure to be swung aroundto the extent desired. It is obvious that the eccentric P could be soplaced that the rod N will be pushed inward to lift the structure bypressing down the lever Q instead of pressing said lever up. Such slightchange is merely mechanical and such as any skilled mechanic mightmakeand is too obvious to need illustration.

An adjusting pin or screw F can be passed through the bearing-block f,so that by causing it to project below the bearing-block the block ispractically made thicker at that point and the structure accordingly canbe raised higher from off the floor.

By the construction described an ordinary domestic chair can be used andit will be given all the movements of a specially-constructed costlydental chair. Furthermore, the several parts can be be easily takenapart; in a short time without the use of special tools and without theservices of a skilled mechanic,

and they can be compactly packed into a small space for convenience andsaving of expense in transportation. The parts are also simple, strong,and durable and render thesupport comparatively inexpensive toconstruct.

We provide arms for the chair composed of a horizontal bar R andvertical bar S, the two being connected together by a hinge T. The bar Sat its lower end is provided with a clasp-U to pass around the leg ofthe chair, as illustrated, and be clamped thereto by suitable means,While the outer end of the bar R is provided with a similar clasp U topass around the back post of the chair, as illustrated, and be clampedthereto by suitable means. These arms can be easily applied and detachedwhen necessary to have arms to the chair.

Instead of using the particular means illustrated in Fig. 2 for securingthe upper portion of the chair to the rod V we may employ the modifiedform of bracket T, (illustrated in Fig. 11,) where the arms U areillustrated as in a curved form, with sockets e at their ends intendedto receive the back posts of a chair.

posts and be clamped thereto by the bolts 6 The bracket will be providedwith the socket for the bar V, the same as shown in Fig. 2 of thedrawings. The head-rest can beomitted when desired, as it is notnecessary.

Instead of forming the clamping-band G separate from the upright portionof the T,

These sockets will preferably be made so that they can be sprung aroundthe back as shown in Fig. 13, we may form the clamp integral with theportion B of the base, as illustrated in Fig. 1.

We have described what we consider to be the best construction; but itis obvious that changes can be made without departing from the spirit ofour invention, and therefore we wish it understood that we do notconfine ourselves to such details of construction.

Having described our invention and set forth its merits, what we claimis 1. In a dental-chair support, thecombiua tion of a base, anuprightstandard, a sleeve secured on said standard, arms extendinglaterally from the said sleeve, sockets mounted on said arms, adapted toreceive. the feet of a chair, and a support for the chairback,substantially as described.

2. In a dental-chair support, the combina tion of a base, an uprightstandard, a sleeve adj ustably secured on said standard, arms extendinglaterally from the said sleeve, the laterally-adjustable sockets mountedon the said arms, adapted to receive the feet of the chairs, varying asto the width between their legs, and a support for the chair-back,substantially as described.

3. In a dental-chair support, the combination of a base, an uprightstandard, a sleeve adj ustably secured on said standard, arms extendinglaterally from the said sleeve, the r0- tatable sockets mounted on thesaid arms, adapted to receive the feet of a chair and to be moved withthe same on the tilting of the chair, and an adjustable support for thechairback, substantially as described.

4. In a dental-chair support, the combination of the base, the uprightstandard, the sleeve adjustably secured on the said standard, the armsprojecting laterally from the sleeve, the rotatable andlaterally-adjustable sockets mounted on the said arms to receive thelegs of chairs, varying as to the width between their legs, and to movewith the legs on tilting the chair, and an adjustable support for thechair-back, substantially as described.

5. In a dental-chair support, the combination of a base, an uprightstandard, a sleeve adjustable on said standard,the arms carried by thesleeve, the sockets made in sections to be adjustable to chair-legs ofvariable sizes mounted on said arms, and a support for the chai-r-back,substantially as described.

6. In a dental-chair support, the combination, with a base-support, ofthe back-support consisting of a rod and hooks secured on its ends, oneof the said hooks being adjustable, and the brace-rod hinged at its endsto the supports, substantially as described.

7. In a dental-chair support, the combination of a base-support, theback-support consisting of a rod, a hook secured .to the upper end ofthe rod, the bracket secured to the lower end of the rod, and means forsecuring the said bracket to the chair-back, and the esaseo brace-rodhinged at its ends to the said support, substantially as described.

8. In a dental-chair support, the combination,with a base-support, of asupport for the back of the chair, comprising a rod provided with hooksto engage a portion of the chair, at least one of which hooks isvertically adjustable on the rod, a brace-rod hinged at its ends to thesaid supports, and a hinged connection between said back-support andbracerod, substantially as and for the purposes set forth.

9. In a dental-chair support, the combination, with a base-support, of asupport for the back of the chair, comprising a rod having a slittedsleeve carrying a hook to engage a partof the chair, means for clampingsaid sleeve to its rod, a brace-rod hinged at its ends to the saidsupports, and a hinged and detachable connection between said brace-rodand sleeve, substantially as and for the purposes set forth.

10. In a dental-chair support, the combination,with a base-support,ofasupport for the back of a chair, provided with means for securing achair thereto, a sectional brace-rod hinged at one end to saidback-support and atthe other end with the base-support and formed withteeth,a pinion supported byone section of said brace-rod and engagingsaid rack-teeth, and means for turning said pinion to adjust the lengthof the brace-rod and lock it to its adjustment, substantially as and forthe purposes set forth.

11. In a dental-chair support, the combination, with the chair-backsupport for the attachment of achair, of a head-rest bar, an arm hingedat one end to said bar and at the other end to said back-support, asegmental brace attached at one end to said back-support and at theother to said hinged arm, a segmental brace connected at one end to saidhead-bar and at the other end to said hinged arm, and a clamp forsecuring said braces in their adjustment to said hinged arm,substantially as and for the purposes set forth.

12. In a dental-chair support, the-combination, with the base-supportand the standard provided with an adjustable sleeve carrying sockets forthe legs of a chair, of an adj ustable back-support for the upper partof the chair, the brace-rod hinged at its ends to the said support, anda head-rest supported from said back-support and adjustable bothvertically and to the inclination of the chair, substantially as and forthe purposes set forth.

13. In a dental chair, the combinatiomwith a base-piece, of asuperstructure sliding vertically on said base-piece and having feet torest upon a floor, a wedge fitting between said'base-piece and a portionof the superstructure, and an eccentrically-actuated rod for forcingsaid wedge between the base-piece and superstructure to raise and lowerthe feet of the structure from and to the floor, substantially as andfor the purposes set forth.

IOC

14. In a dental chair, the combination,with a base-piece, of asuperstructure sliding ver tically on said base-piece and having feet torest upon a floor, a hollow arm to said superstructure, and aneccentrically-actuated rod working in said arm and carrying a Wedge tobe forced between the base-piece and the superstructure to raise thesuperstructure and lift its feet from off the floor to permit thesuperstructure to be easily revolved, substantially as and for thepurposes set forth.

15. In a dental chair, the combination, with V a base-piece, of asuperstructure sliding verti cally on said base-piece andhaving feetresting upon a floor, a wedge fitting between said base-piece and-aportion of the superstructure, and the screw passing through the saidportion of the superstructure to form an adjustable bearing for thewedge, substantially as described.

16. In a dental chair, a detachable footrest consisting of the bars D,joined at their inner ends to form a guide and clamp, the board carriedon the outer ends of the said bars, the suspending-arms pivoted to thesaid rods and provided with books at their upper ends, the segmentconnected at one end to the said suspending arms and the free endpassing through the guide or clamp formed in the inner ends of the barsD, and the screw for clamping the guide, substantially as described.

17. In a dental chair, a removable arm consisting of the arm proper, thestandard hinged to the front end of the arm, and the clamps or collarsattached to the lower end of the standard and the rear end of the armproper for the purpose of securing the arm to the front leg and backpost of its respective side, substantially as described.

In testimony whereof we affix our signatures in presence of twowitnesses.

FRANK HENRY FIELD. CHARLES HARMAN FIELD. Witnesses to Frank H. Field:

0. EDMUND KELLS, J r., E. J BARNETT. Witnesses to Charles H. Field:

W. P. HAMILTON, J. A. LONGLEY.

